Electrical switches



0a. 16, 1956 s. LEVINE 2,767,268

ELECTRICAL SWITCHES Filed Dec. 24, 1953 INVENTOR. 1,: O [a W 5AM LEV/NE Arrow/5K5 United States Patent ELECTRICAL SWITCHES Sam Levine, Irvington, N. J., assignor to John Gombos Co., Inc., Irvington, N. J.

Application December 24, 1953, Serial No. 400,291

Claims. (Cl. 20061.39)

This invention relates to electrical switches and more particularly to a direction sensor electrical contact switch.

it is an object of the instant invention to provide a switch in which one set of contacts is closed if rotation is clockwise while still another set is closed if rotation is counterclockwise.

A further object is to disclose a single pole, double throw switch with a spring-loaded return to a center off position.

Another object is to disclose a switch of the type described available for panel use with electronic or electrical equipment in which the direction of rotation of the selector knob closes the desired circuit.

Other objects of the instant invention will become apparent in the course of the following specification;

In the attainment of the aforesaid objectives, subject switch is made in three embodiments. In the first embodiment, a shaft is rotatably inserted through a frame and a detent is keyed to the shaft. An inverted U-shaped swinging contact arm straddles the detent with the downwardly extended ends of the arm rotatable on the shaft, the arm being limited in its rotation by two spaced stationary contacts which also serve as stops for the contact end of the arm. A contacting roller is inserted between the inverted U-shaped arm in engagement with the undulating edge of the detent and is maintained longitudinally adjustable in the arm and under downwardly directed tension against the detent. An indexing roller is also provided and so positioned that both the contacting and indexing rollers are in a trough of the undulating peripheral edge of the detent simultaneously. The second embodiment is like the first except that the detent is a segment while the swinging contact arm is a leaf spring having one end rotatable on the shaft and the free end normally intermediate two fixed contacts. A roller or ball entrapped along the undulated periphery of the detent is maintained under tension against the detent by a spring arm one end of which is secured to the swinging contact arm. The first two embodiments actually disclose momentary contact switches and the third embodiment is like the first or the second except that the stationary contacts and the swinging contact are of such form that the engagement of the swinging contact arm with either stationary contact is other than momentary.

The invention will appear more clearly from the following detailed description when taken in conjunction with the accompanying drawings showing by way of example tie preferred embodiment of the inventive concept.

in the drawings:

Figures 1-3 show the first embodiment of the switch constructed in accordance with the principles of this invention, and in which:

Figure l is a rear elevational view of the switch;

Figure 2 is a sectional view along the line 2-2 of Fig. l; and

Figure 3 is a sectional view along the line 3-3 of Fig. 1.

ICC

Figures 4-6 show the second embodiment of the switch and in which:

Figure 4 is a side elevational view of the switch;

Figure 5 is an elevational view of the back of the switch shown in Figure 4; and

Figure 6 is an enlarged fragmentary view of the contact arm and detent.

Figure 7 is a fragmentary perspective view of the third embodiment of the switch.

Referring now in greater detail to the first embodiment of subject switch shown in Figures 1-3 where like reference numerals indicate like parts, reference numeral 10 indicates a frame; 11 a shaft rotatable in the frame; 12 a detent keyed to the shaft and having an undulated peripheral edge; 13 an inverted U-shaped swingable arm straddling the detent with the downwardly directed ends of the U-shaped arm rotatable on the shaft; 14 a contacting roller in operable engagement with the undulated peripheral edge of the detent; 15 a contact arm extension on the horizontal portion of the inverted U-shaped arm and designed to be brought into junta-position with the spaced fixed contacts 16, 17; and 18 indicates an indexing roller for the detent.

The frame it is made from electrically insulated material or even from electrically conductive material if the later described contacts 15, 16, 17 are insulated from each other. The frame 10 is constituted of the upright front member 19, the base member 26, and the upright back member 21, with the front and back member secured to the base member along corresponding edges. Through the front and back members are the aligned openings 22, 23 (Fig. 2), respectively, and which may carry the bearings Z4, 25.

The shaft 11 is made from any suitable material and is rotatably inserted in the bearings 24, 25 with one end protruding through the front member 19 as most clearly shown in Figure 2 for the attachment of a knob (not shown).

The detent 12 is also made from any suitable material and is keyed in a suitable manner to the shaft 11. The peripheral edge of the detent is undulated as shown in Fig. l.

The inverted U-shaped swingable contact arm 13 straddles the detent 12 and through the downwardly directed ends of the arm are aligned openings through which the shaft 11 is rotatably inserted but in slight frictional en gagement therewith. On the horizontal portion 26 (Fig. 2) of the arm 13 is a contact arm extension 15 which protrudes upwardly between the two fixed and spaced contacts 16, 17 each of which is secured to the frame in a known manner and in a plane substantially parallel to a vertical plane through the detent. in each of the downwardly directed sides of the inverted U-shaped arm 13 are the similar longitudinal slots 27, 28 (Figs. 1 and 2).

The contacting roller 14 is mounted upon and rotates with a shaft 29 which protrudes from each end of the roller and is longitudinally slidable in the slots 27, 28. Similar spiral springs 30, 31 one on each side of the inverted U-shaped member and having one end attached to the shaft 29 and the opposite end attached to the inverted U-shaped member under tension maintains the contacting roller 14 under downwardly directed tension against the undulated peripheral edge of the detent 12.

The indexing roller 18 is rotatably secured between-any suitable members, one of which is shown as 32 in Figure 1, the members being extended in spaced relationship from adjacent the free end of a leaf spring 33 one end of which is anchored to the front member 19 by any suitable means 34. The indexing roller 13 is so positioned that it will always be in the trough of one undulation when the contacting roller 14 is in the trough of another undulation.

In operation:

Assume that the fixed contacts 16, 17 are mounted in spaced relationship on a support and electrically insulated from each other in a well known manner.. Assume" further that the conductor 36 is electrically connected to the fixed contact 16, the conductor 37 to the fixed contact 17, the conductor 38 to the swinging contact arm extension 15 by the flexible conductor 39, and that it is desired to interconnect momentarily the conductors 36, 38. Merely turning the shaft 11 counterclockwise (Figure 1) will bring the swingable contact arm extension 15 into momentary electrical engagement with the fixed contact 16 to close the circuit. The circuit will be opened automatically when the knob (not shown) for turning the shaft 11 is released. By turning the shaft 11 clockwise the conductors 37, 38 are brought into momentary contact in a like manner. The only stable position of the contacting roller 14 is in a trough of the undulated peripheral edge of the detent 12 when the swingable contact arm extension 15 will be centered between the fixed contacts 16, 17 as shown in Figure 1. Thus due to the provision of the undulations in the detent 12 and also due to the pressure of the roller 14 against the detent 12, the arm extension 15 will return to its central position as soon as pressure thereon is released.

Referring now to the second embodiment of the switch 7 shown in Figures 4-6, reference numeral indicates a frame; 51 a shaft rotatably disposed in the frame; 52 a fragmentary detent keyed to the shaft; 53 a swingable contact arm the downwardly directed end of which is rotatably on the shaft; 54 a contacting roller or ball in operable engagement with the undulated peripheral edge of the detent; 55a an extension arm one end of which is attached to the swingable contact arm with the opposite end under downwardly directed tension against the roller or ball; and 55, 56 fixed contacts between which the free end of the swingable contact arm is inserted.

The frame 50 is constituted of a base member 57, a front member 58, and a top member 59, the base and top member being integrally formed with or otherwise secured along corresponding edges of the front member or vice versa.

One end of the shaft 51 is rotatably inserted in the base member 57 with the free end protruding therefrom.

The fragmentary detent 52 is keyed to the protruding end of the shaft 51 and is upwardly directed therefrom as illustrated. The upper peripheral edge of the fragmentary detent is undulated and there may be a rim on both sides 'of the undulated edge to prevent the roller or ball from rolling off.

The fixed contacts 55, 56, are attached in any known manner to the top member 59 in spaced relationship with each other and in a plane substantially parallel to a vertical plane through the fragmentary detent.

The swingable contact arm 53 at the bottom is turned around the shaft 51 on which it is rotatable. The top of the arm 53 extends upwardly between the fixed contacts 55 and 56. On the arm 53 is an extension arm 55:: one end of which is attached to the swingable contact arm with the free end extended outwardly in substantially L-shape (Fig. 6) over the roller or ball 54 and under downwardly direct tension thereagainst.

To prevent the fragmentary detent from passing from under the roller or ball '54, the stops 60, 61 are suitably positioned on the base member 57 and on opposite sides of the fragmentary detent.

The operation of the switch of the second embodiment will be apparent from the foregoing.

Referring now to the third embodiment of the switch fragmentarily shown in Figure 7, reference numeral 79 indicates the upper portion of a swingable contact arm actuated by the mechanism of either the first or second embodiment previously described and illustrated and differing therefrom only in the construction of the fixed and swingable contacts.

The upper portion of the swingable contact arm is made in the shape of a blade, similar to the blade used in the known knife switch, for engagement with stationary spring clips 71, 72 fastened in a known manner to a block 73. The opposed portions 71a, 71b in the case of the clip 71, and 72a, 72b in the case of the clip 72 are under inwardly directed tension so that the blade of the swingable contact arm 70 when moved between the opposed portions of the clip is held therein under tension and against, in the first embodiment, the tension of the springs 3t 31, or in the second embodiment, against the tension of the extension arm 55a.

A conductor 71c connects the spring clip 71, a conductor 72c the spring clip 72, while a conductor 70a is connected to the contact arm 7t) through the flexible conductor 7%. Obviously, the stationary spring clip 71, 72 and the swingable contact arm 7d are electrically insulated from each other.

A design requirement for the device of the third embodiment is that the opposed portions 71a, 71b and 72a, 72b shall exert a holding force on the swingable contact arm 70 that is slightly greater than the component of force due to the springs 30, 31 of the first embodiment or the component of force of the extension arm 55a of the second embodiment both of which tend to restore the swingable contact arm to the center off position. Under the conditions of the third embodiment, once the shaft is rotated, one set of contacts will be closed and will remain closed until the direction of rotation of the shaft is reversed. When the direction of rotation of the shaft is reversed, the component of force transmitted from the shaft through the detent to the roller, thence to the swingable contact arm plus the restoring force of the springs is sufiicient to break the set of contacts that have been closed and close the opposite set of contacts.

While there are above disclosed but a limited number of embodiments of the structure herein presented, it is possible to produce still other embodiments without departing from the inventive concept herein disclosed, and it is desired that only such limitations be imposed on the appended claims as are stated therein.

What is claimed is:

1. A direction sensor electrical switch comprising a frame, a shaft rotatably disposed in said frame, a detent keyed to said shaft, a swinging contact arm rotatable on said shaft, a roller coacting with said detent, means on said swinging contact arm for maintaining said roller under tension against said detent, and a fixed contact disposed on said frame on each side of said swinging contact arm and coacting therewith.

2. A direction sensor electrical switch comprising a frame, a shaft rotatably disposed in said frame, a detent keyed to said shaft, two fixed contacts disposed on said frame above said detent and in spaced relationship with each other, a swingable contact arm coacting with said fixed contacts at one end and at the opposite end rotatable on said shaft, a roller in operable engagement with said detent, means on said swinging contact arm for maintaining said roller under tension against said detent, and indexing means for said detent.

3. A director sensor electrical switch comprising a frame, a shaft rotatably disposed in said frame, a detent keyed to said shaft, two fixed contacts disposed on said frame in spaced relationship with each other and substantially above said detent in a plane substantially parallel to a vertical plane therethrough, an inverted U-shapcd contact arm straddling said detent with the downwardly directed ends of the arm rotatable on said shaft, each side of the inverted U-shaped contact arm having a longitudinally directed slot formed therein, a contacting roller rotatably disposed in the slots and in operable engagement with the detent, spring tension means for maintaining said roller under tension against said detent, a contact arm extension disposed on the horizontal portion of said inverted U-shaped contact arm and coacting with said fixed contacts, and indexing means for said detent.

4. A direction sensor electrical switch according to claim 3 in which the fixed contacts comprise spring clips, each spring clip comprising opposed portions under inwardly directed tension, and in which the contact arm extension comprises a blade held under tension between the opposed portions of each spring clip when moved therein.

5. A direction sensor electrical switch comprising a frame, a shaft for the frame, one end of said shaft being disposed in the frame With the free end protruding therefrom, a fragmentary detent keyed to said shaft and up wardly directed therefrom, a stop disposed on said frame on each side of said fragmentary detent and coacting therewith, two fixed contacts disopsed on said frame in spaced arrangement With each other and substantially above said fragmentary detent in a plane substantially parallel to a vertical plane therethrough, a swingable contact arm for said shaft, one end of said arm being rotatable on said shaft with the opposite end intermediate said fixed contacts, a contacting roller in operable engagement with said detent, and an extension arm protruding from said swingable contact arm with the free end under downwardly directed tension against said roller.

References Cited in the file of this patent UNITED STATES PATENTS 1,179,108 Kaisling Apr. 11, 1916 1,355,701 Savage Oct. 12, 1920 1,690,414 Kemble Nov. 6, 1928 1,725,256 Claytor Aug. 20, 1929 1,950,278 Tsavaris Mar. 6, 1934 2,427,453 Hadley Sept. 16, 1947 2,432,682 Robson Dec. 16, 1947 2,675,442 Van Ryan Apr. 18, 1954 FOREIGN PATENTS 487,658 Great Britain June 23, 1938 

